“Curators at the University of California at Santa Barbara’s Donald C. Davidson Library have digitized 6,000 late 19th-century and early 20th-century wax and plastic cylinder recordings — precursors to the flat record. The audio, which includes ragtime hits, vaudeville routines and presidential speeches, encapsulates history with crackles and hisses, but archivists say preserving the sounds now is vital because the cylinders are deteriorating.”